High Vertical Load Box

ABSTRACT

A box, preferably made from a unitary blank of material. The box has four interconnected sidewalls defining an open storage area that has a generally rectangular prism shape. Each sidewall defines at least a triple thickness of the material. The preferred material is corrugated paper or plastic.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/185,734 filed on Jun. 10, 2009, the entire contents of which are expressly incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to boxes made from corrugated materials.

BACKGROUND OF THE INVENTION

File storage boxes typically have single or double thickness sidewalls. When these boxes are full of files, they are heavy. When full boxes are stored one on top of another, the cumulative weight can crush boxes toward the bottom of the pile. Accordingly, there is a need for file storage boxes that can support greater vertical loads, but are assembled in essentially the same manner as other file storage boxes.

SUMMARY OF THE INVENTION

This invention features boxes for file storage and the like. The inventive box is made from a unitary blank of material. The box, when assembled, has four interconnected sidewalls that define an open storage area between them. The sidewalls are typically each rectangular in shape, to define a generally rectangular prism-shaped storage area. When the box is fully assembled each sidewall comprises a triple thickness of material, or the sidewalls could be of quadruple or greater thickness if such is necessary. In one embodiment the box is made from a corrugated material such as corrugated paper or corrugated plastic. Preferably the corrugations run in the same direction for each thickness of the sidewall. Corrugations are stronger with loading in the direction parallel to the direction of the corrugations. Accordingly, the preferred arrangement is with the corrugations in each of the three thicknesses of each sidewall running in the direction of (i.e., parallel to) the height of the sidewalls.

One embodiment of this invention features a box made from a unitary blank of material comprising four interconnected sidewalls defining an open storage area having a generally rectangular prism shape, each sidewall comprising at least a triple thickness of the material and a bottom closing the storage area at one end of the sidewalls. The sidewalls may each be formed from three sidewall panels. The blank may be made from a corrugated material, and the sidewall panels may be arranged such that the corrugations in the sidewall panels all run in the same direction. The corrugations preferably run in a direction parallel to the height of the sidewalls.

The blank may define four portions, each portion making up one of the sidewalls and part of the bottom. Each portion may define three interconnected sidewall panels, each such sidewall panel making up one thickness of a triple thickness sidewall. The two sidewall panels closest to one end of each of the portions may be separated from the two such sidewall panels of each adjacent portion by a gap, so that the two sidewall panels can move independently of the sidewall panels of any other portion. The three sidewall panels of each portion may be interconnected by score lines.

The box may further comprise a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion. The bottom may be formed by four bottom panels, one such bottom panel part of each of the four portions. Two non-adjacent bottom panels may each define via a score line a flap that is glued to an adjacent bottom panel.

In another embodiment the sidewall panel that defines one end of each of the portions is separated from an adjacent sidewall panel of each adjacent portion by a gap, so that such sidewall panels can move independently of the sidewall panels of any other portion. The bottom may be formed by four bottom panels, one such bottom panel part of each of the four portions. The three sidewall panels and the bottom panel of each portion may be interconnected by score lines, wherein each bottom portion is connected to two sidewall portions. The box may further comprise a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion.

Featured in another embodiment is a box made from a unitary blank of material and a separate sleeve. This embodiment comprises four interconnected sidewalls defining an open storage area having a generally rectangular prism shape, each sidewall comprising at least a double thickness of the material, and a bottom closing the storage area at one end of the sidewalls. A separate rectangular sleeve is placed inside of the storage area in contact with each of the sidewalls, to thicken the sidewalls such that each is formed from at least three sidewall panels. The sleeve can be glued to the sidewalls or can be interference fitted inside the box. The blank and the sleeve are both made from a corrugated material. The sidewall panels in the assembled box are arranged such that the corrugations in the sidewall panels all run in the same direction parallel to the height of the sidewalls.

The blank may define four portions, each portion making up one of the sidewalls and part of the bottom. Each portion may define two or three interconnected sidewall panels, each such sidewall panel making up one thickness of a sidewall. The one or two sidewall panels closest to one end of each of the portions may be separated from the sidewall panels of each adjacent portion by a gap, so that these sidewall panels can move independently of the sidewall panels of any other portion. The sidewall panels of each portion may be interconnected by score lines. The box may further comprise a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion. The bottom may be formed by four bottom panels, one such bottom panel part of each of the four portions. The two non-adjacent bottom panels may each define via a score line a flap that is glued to an adjacent bottom panel. In another embodiment the sidewall panels and the bottom panel of each portion are interconnected by score lines, and each bottom portion is connected to two sidewall portions. The box may further comprise a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 is a top view of the unitary blank of material from which the box of a first embodiment of the invention is made;

FIG. 2 is a view similar to that of FIG. 1 after the first step in creation of the triple-thickness sidewalls, in which the top sidewall panels are folded over to create a double thickness sidewall panel;

FIG. 3 is a perspective view of a partially assembled box according to the first embodiment with the bottom in place, and the four sidewalls partially assembled;

FIG. 4 is a similar perspective view of the fully assembled box of the first embodiment (but without the top);

FIG. 5 is a side view of the box of FIG. 4;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5, showing the triple thickness sidewalls;

FIGS. 7-10 are similar views of a second embodiment of the invention; and

FIG. 11 shows a sleeve used in a third embodiment of the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

A first embodiment of a triple-thickness sidewall box of the invention is shown in FIGS. 1-6. This embodiment is formed from the unitary blank of material 10 shown in FIG. 1. Blank 10 may be constructed of any material that will form a stiff panel surface. Preferably, blank 10 is made from a single thickness corrugated material, which is a material with two layers of linerboard separated by a single layer of fluted material. Such a corrugated material can be constructed from different substances as is known in the art. The material can have several different constructions. Corrugated material is typically constructed from fiber materials or plastic materials. Preferably the corrugations run parallel to the direction of arrow A, FIG. 1. Blank 10 is formed through die cutting and creasing of corrugated material as is known in the art.

Blank 10 comprises first, second, third and fourth sidewall portions 12, 20, 30 and 40, respectively. Portion 12 comprises sidewall panels 13, 14 and 15. Portion 20 comprises sidewall panels 21, 22 and 23. Portion 30 comprises sidewall panels 31, 32 and 33. Portion 40 comprises sidewall panels 41, 42 and 43. Ultimately, each of the sidewall portions ends up forming one of the four generally rectangular sidewalls of the assembled box. When assembled, the four sidewalls define a generally rectangular prism-shaped storage area located between the sidewalls and closed by the box bottom (described below). The standard separate top is not shown in the figures, for the sake of clarity only.

Panels 13, 21, 31 and 41 are separated by fold line 16 from panels 14, 22, 32 and 42, respectively. Small circular openings 121-124 form finger-hole recesses in the finished sidewalls that eases manipulation of them. Fold line 17 separates panels 14, 22, 32 and 42 from panels 15, 23, 33 and 43, respectively. The top two panels of each adjacent sidewall portion (e.g., panels 13 and 14) are separated by a small gap from such panels of each adjacent sidewall portion. The small gap is created via die cutting and separates the sidewall portions. For example, gap 61 defines the upper two-thirds of portions 12 and 20 that are defined by panels 13 and 14, and 21 and 22, respectively. Gaps 62 and 63 likewise create an identical construction of the top two panels of sidewall portions 20, 30 and 40.

Cutouts 101 and 102 and hinged flap 103 (which is cut on three sides) create one handhold opening in sidewall 23, and similar cutouts 111 and 112 and hinged flap 113 create a second handhold opening in sidewall 43; each of the hinged flaps 102 and 113 ends up on the outside of the assembled box and gets pushed through to form a hinged flap which acts as a cushion and reinforcement against cutouts 101 and 102; and 111 and 112, respectively.

Typically, sidewalls 23 and 43 are more narrow than sidewalls 15 and 33 (although this is not a limitation). This creates a rectangular-shaped box, with handholds defined in the two more narrow ends.

Bottom portion 50 is defined by panels 51-54 that are separated from the sidewall portions by fold line 76. The construction of bottom portion 50 is known in the art, and accomplishes an “automatic bottom” that is arranged to automatically close the bottom of the area between the sidewalls as the box form is pushed open into the fully-assembled state, as further explained below. To accomplish this, flap 52 a defined from flap 52 via fold line 71 is glued to flap 51, while flap 54 a defined from flap 54 via fold line 72 is glued to flap 53. Other known bottom styles, such as flaps that are folded by the user during box assembly, can be used instead.

FIG. 2 shows the partially-assembled box 10 a after the first assembly step from the blank 10 shown in FIG. 1. In this assembly step, panels 13, 21, 31 and 41 are folded down along fold line 16 to lie flat on panels 14, 22, 32 and 42, respectively. Preferably (but not necessarily), the two overlapping panels are glued together with an appropriate adhesive to form partially-assembled box 10 a, FIG. 2.

The bottom of the box is then pre assembled by folding flaps 52 a along score line 71 in a reverse fold against flap 52 which is also simultaneously folded along score 76 to lay against panel 23 on the inside of the box. Flap 51 is also folded along score 76 to lie against panel 15. Adhesive is applied to flap 51. The same process occurs on the other side; flap 54 a reverse folds along score 72 to lay against flap 54. Simultaneously, flap 54 is also pulled back to lie against sidewall 43. Flap 53 is pulled back along score 76 to lie against panel 33. Adhesive is applied to flap 54 a. When the bottom folding process is complete, all flaps, 51, 52, 53 and 54 are folded along score 76 and now lie against what becomes the inside sidewalls of the box, panels 15, 23, 33 and 43.

The next step in the assembly is to fold the partially-assembled box 10 a along fold lines 201 and 203 (FIG. 2), glue tab 90 to the outside of panel 15 and glue together the appropriate panels of bottom portion 50 as described above. This results in a generally flat tubular box form. When completed in the tubular form, flap 52 a is now joined with flap 51, flap 54 a is joined with flap 53, and flap 90 is joined with panel 15. The two diagonal corners of the box form are then pushed toward one another. This assembles bottom portion 50 into a bottom that spans the area between the bottoms of the sidewalls and forms the four side panels into a box shape to create the further partially-assembled box 10 b, FIG. 3.

The final step in the assembly is to fold over and push sidewall panels 14, 22, 32 and 42 down into the box along fold line 17 such that panels 13, 21, 31 and 41 lie against panels 15, 23, 33, and 43, respectively. This forms triple thickness sidewalls with the corrugations in each thickness running in the same direction, parallel to the height of the sidewalls, as shown in FIG. 6. This construction creates high vertical loading strength that helps to prevent boxes from being crushed when one or more heavy boxes or other loads are placed on top of the box. In one non-limiting example, a triple sidewall box made according to the invention utilizing 32 ECT grade of paper corrugated yielded a top-to-bottom compression strength of 1,500 pounds, which is approximately double the average for a letter/legal size (15L×12W×10″H) file box.

A second embodiment of a triple-thickness sidewall box of the invention is shown in FIGS. 7 through 10. This embodiment is also formed from a unitary blank of material. The blank 200 is shown in FIG. 7, and also may be constructed of any material that will form a stiff panel surface as with the first embodiment shown in FIGS. 1 through 6.

Blank 200 is also formed through die cutting and creasing of corrugated material. Blank 200 comprises first, second, third and fourth sidewall portions 210, 230, 250 and 270, respectively (dimensions in inches are shown in the drawing; such dimensions illustrate one size blank that creates a standard file box, and are not a limitation of the invention). Portion 210 comprises panels 211, 212, 213 and 214. Portion 230 comprises panels 231, 232, 233 and 234. Portion 250 comprises panels 251, 252, 253 and 254. Portion 270 comprises panels 271, 272, 273 and 274. Ultimately, each of the four sidewall portions ends up forming one of the four generally rectangular sidewalls of the assembled box, as well as a portion of the bottom of the assembled box. Handholds are created in the same manner as with the first embodiment, via cutouts 256, 259, 216 and 219, and hinged flaps 257 and 217 (cut out on three sides with the fourth side scored). When assembled, the four sidewalls define a generally rectangular prism-shaped storage area located between the sidewalls enclosed by the box bottom. The top is not shown in the figures, for the sake of clarity only.

Blank 200 is first folded in half along horizontal fold line 301. The blank is then folded along vertical fold lines 305 and 307; elongated cutouts 237, 261 and 285 facilitate bending along lines 307, 306 and 305, respectively. The underside of tab 220 is then glued to the left-most portion of panel 272. The resulting flat tubular form is then expanded into a rectangular form by pulling apart the corner where panel 232 meets panel 252 and the corner where panel 212 meets panel 272. This causes the shapes created from the bottom-forming panels 213, 233, 253 and 273, partially defined by cutouts 218, 236, 258, 260, 276 and 279, to inter-fit: this type of self-forming bottom is known in the art such as illustrated in a number of patents issued to R. E. Paige, including U.S. Pat. Nos. 2,577,588; 2,843,308; 3,278,108; 3,430,840; and 4,182,477. The resulting partially-assembled box is shown in FIG. 8.

A rectangular tubular “sleeve” connected to the bottom is created by panels 214, 234, 254 and 274. This tubular sleeve is then pushed down so that these four panels sit adjacent to panels 212, 232, 252 and 272, respectively. This effectively creates four double-thickness sidewalls. The partially-assembled box after these steps have been completed is shown in FIG. 9. Elongated cutouts 281-283 help to create the separate upstanding flaps 211, 231, 251 and 271.

The final step in construction is to push vertically-extending flaps 211, 231, 251 and 271 down into the box form by folding them along horizontal fold line 302, FIG. 9. This creates the fully-assembled box shown in FIG. 10. Each of the four sidewalls is formed of three thicknesses of single-wall construction, thus creating triple-thickness sidewalls that have high vertical force loading. Finger holes 277 and 238 in panels 274 and 234, along with the diverging fold lines in these two panels, allow these panels to be pulled together towards the center of the box to assist with collapsing or disassembling the fully assembled box from the formed shape back to the flat tubular shape, if desired.

A third embodiment of a triple, quadruple or greater thickness sidewall box of the invention can be accomplished with any single or double thickness sidewall box, such as the boxes taught in the Paige patents and the first embodiment of the present invention referred to above, with an additional single thickness or double thickness sidewall sleeve 350, FIG. 11, added inside the box. Sleeve 350 can be glued into the box or can be left loose to rely on an interference fit with the sidewalls of the double sidewall box. If desired, finger holes and appropriate creases, such as shown in panels 234 and 274 of blank 200, FIG. 7, can be added to facilitate adding sleeve 350 to, or removing it from, a double (or single) sidewall box.

The vertical loading ability of the box of this invention can be adjusted by making the blanks of appropriate materials and material thicknesses. Further, a box with sidewalls of quadruple or greater thickness can be accomplished by proper design of the sidewall sleeve. For example, a box with six thickness sidewalls could be made by creation of the blank from a double sidewall material. Other options and variations will occur to those skilled in the art.

The various aspects shown in some drawings and not others may be combined or used in other manners as would be apparent to those skilled in the art. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention. 

1. A box made from a unitary blank of material, comprising: four interconnected sidewalls defining an open storage area therebetween having a generally rectangular prism shape, each sidewall comprising at least a triple thickness of the material; and a bottom closing the storage area at one end of the sidewalls.
 2. The box of claim 1 in which the sidewalls are each formed from three sidewall panels.
 3. The box of claim 2 in which the blank is made from a corrugated material, and the sidewall panels are arranged such that the corrugations in the sidewall panels all run in the same direction.
 4. The box of claim 3 in which the corrugations run in a direction parallel to the height of the sidewalls.
 5. The box of claim 4 in which the blank defines four portions, each portion making up one of the sidewalls and part of the bottom.
 6. The box of claim 5 in which each portion defines three interconnected sidewall panels, each such sidewall panel making up one thickness of a triple thickness sidewall.
 7. The box of claim 6 in which the two sidewall panels closest to one end of each of the portions are separated from the sidewall panels of each adjacent portion by a gap, so that the two sidewall panels can move independently of the sidewall panels of any other portion.
 8. The box of claim 7 in which the sidewall panels of each portion are interconnected by score lines.
 9. The box of claim 8 further comprising a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion.
 10. The box of claim 9 in which the bottom is formed by four bottom panels, one such bottom panel part of each of the four portions.
 11. The box of claim 10 in which two non-adjacent bottom panels each define via a score line a flap that is glued to an adjacent bottom panel.
 12. The box of claim 6 in which the sidewall panel that defines one end of each of the portions is separated from an adjacent sidewall panel of each adjacent portion by a gap, so that such sidewall panels can move independently of the sidewall panels of any other portion.
 13. The box of claim 12 in which the bottom is formed by four bottom panels, one such bottom panel part of each of the four portions.
 14. The box of claim 12 in which the three sidewall panels and the bottom panel of each portion are interconnected by score lines, wherein each bottom portion is connected to two sidewall portions.
 15. The box of claim 14 further comprising a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion.
 16. A box made from a unitary blank of material and a separate sleeve, comprising: a unitary blank of material that defines four interconnected sidewalls defining an open storage area therebetween having a generally rectangular prism shape, each sidewall comprising at least a double thickness of the material, and a bottom closing the storage area at one end of the sidewalls; and a separate sleeve inside of the storage area and in contact with each of the sidewalls, to thicken the sidewalls such that each is formed from at least three sidewall panels; wherein the blank and the sleeve are both made from a corrugated material, and the sidewall panels are arranged such that the corrugations in the sidewall panels all run in the same direction parallel to the height of the sidewalls.
 17. The box of claim 16 in which the blank defines four portions, each portion making up one of the sidewalls and part of the bottom.
 18. The box of claim 17 in which each portion defines two or three interconnected sidewall panels, each such sidewall panel making up one thickness of a sidewall.
 19. The box of claim 18 in which the two sidewall panels closest to one end of each of the portions are separated from the sidewall panels of each adjacent portion by a gap, so that the two sidewall panels can move independently of the sidewall panels of any other portion.
 20. The box of claim 19 in which the sidewall panels of each portion are interconnected by score lines.
 21. The box of claim 20 further comprising a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion.
 22. The box of claim 21 in which the bottom is formed by four bottom panels, one such bottom panel part of each of the four portions.
 23. The box of claim 22 in which two non-adjacent bottom panels each define via a score line a flap that is glued to an adjacent bottom panel.
 24. The box of claim 18 in which the sidewall panel that defines one end of each of the portions is separated from an adjacent sidewall panel of each adjacent portion by a gap, so that the such sidewall panels can move independently of the sidewall panels of any other portion.
 25. The box of claim 24 in which the bottom is formed by four bottom panels, one such bottom panel part of each of the four portions.
 26. The box of claim 24 in which the sidewall panels and the bottom panel of each portion are interconnected by score lines, wherein each bottom portion is connected to two sidewall portions.
 27. The box of claim 26 further comprising a tab projecting from and connected by a score line to one sidewall panel of one portion, wherein the tab is glued to a sidewall panel of another portion. 